How the simulator works.
A walkthrough of every column, number, and action in the Keyword Coverage Simulator — written for people already inside the product who want to understand what they're looking at.
The three columns
The simulator is a fixed 3-column workspace: Live store on the left, Draft editor in the middle, Saved simulations on the right. Whichever card is active in the right column drives every number you see.
Full simulator at /apps/{id}/keywords/simulator — all three columns visible.
Live store
Read-only mirror of your current App Store / Play Store metadata for the active country. Updates only when our scraper detects a change. This is the ground truth every draft is compared against.
Draft editor
Editable fields — title, subtitle, keyword field on iOS; title, short description, full description on Android. Type freely; the simulator runs in the background (debounced 400ms) and updates the right column.
Saved simulations
Stack of named drafts. The "+ New draft" card up top creates a fresh blank; the LIVE card pinned at the bottom is a shortcut back to the live snapshot. Clicking a saved card loads it into the editor.
Reading the coverage ledger
Below the editor, every tracked keyword in the active country lists with a status chip. The chip is purely structural — it tells you whether your metadata's tokens match the keyword's tokens, not whether you'll rank for it.
- coveredLive and draft both contain the keyword. No change.
- gainedDraft contains the keyword, live doesn't. You'd start being indexed for it.
- lostLive contains the keyword, draft doesn't. A wording change cost you eligibility.
- uncoveredNeither version contains the keyword. Tracked but unaddressed.
Coverage is a literal regex match against your title, subtitle, keyword field (iOS), short description (Android), and description. Same logic the App Store uses to decide whether you're eligible to appear in a search — not where you'll rank.
The coverage ledger with at least one covered, gained, lost, and uncovered row visible. Filter chips at the top (ALL · COVERED · UNCOVERED · GAINED · LOST).
TMS — the headline number
TMS (Total Market Searches) is the headline numeral above the ledger. It's the sum of estimated monthly searches for every keyword your draft covers, across all your tracked keywords for the active country.
Read it as a ceiling, not a forecast. TMS measures the size of the search pool you're eligible for — not how many of those searches you'll actually capture. Capturing them depends on where you rank, your conversion rate, and how much paid placement Apple or Google injects above you.
The chip below the numeral shows the delta vs. live: +12,400 means your draft would expand the eligible pool by that many monthly searches; −3,100 means you'd shrink it.
The TMS hero numeral with a positive delta chip (e.g. +12,400) — capture during a draft that gains coverage.
Untapped reach & AI fill
A sticky panel above the ledger lists every uncovered keyword with its estimated monthly searches (MaxReach). Tick the keywords you want to address — the panel sums them in real time and shows the additional reach you'd capture.
Two ways to fill the gaps
- Edit fields by hand. Just type the missing terms into the title, subtitle, keyword field, or description. The ledger reclassifies as you type.
- Let AI do it. With keywords selected, click Generate. AI proposes two variants: AMEND (preserve all existing tokens, add the gaps) and REWRITE (full restructure, may drop low-value tokens). Both are auto-saved as new drafts so you can compare them against each other and against your manual edit.
On iOS, AMEND respects the 100-byte keyword-field limit and avoids duplicates against your title and subtitle (Apple penalises repetition). If a target keyword can't fit, the AI reports it as skipped with a reason.
The sticky untapped-reach panel with 3-5 keywords ticked and the "+X searches/month" total visible. The Generate button should be enabled.
Saved-simulations column right after a successful Generate — showing both the AMEND and REWRITE cards with their ✦ NEW badges and TMS deltas.
Saving and comparing drafts
Drafts are explicit-save — typing in the editor doesn't automatically persist anything. Three actions create or update saved rows:
- Save — writes the current draft into the active simulation card (or creates a new one if you started from LIVE).
- Save as new — always creates a new card, leaving the active one untouched. Use this to fork a variant.
- Rename / Duplicate / Delete — per-card actions on the right. All three use in-app modals (no native browser dialogs).
Switching between saved cards reloads the editor with that card's draft and recomputes the ledger against today's tracked keywords and volume data — not a frozen snapshot. So a draft saved two weeks ago will surface fresh insights if your tracked keywords or volume signals have moved since.
Saved-simulations column with 4-5 cards: "+ New draft" at the top, two or three saved drafts (one active with the accent left rule), and the LIVE card pinned at the bottom.
What "reach" actually means
Three things the simulator's reach numbers are, and one thing they aren't:
- Are: a per-keyword estimate of monthly search volume in the active country.
- Are: summed into TMS only over keywords your metadata's tokens actually match.
- Are: useful for prioritisation — bigger gaps deserve attention before smaller ones.
- Aren't: install forecasts. Indexing makes you eligible; ranking captures the searches.
The simulator can prove your draft is eligible to appear for a keyword. It can't tell you which slot you'll land in — that depends on competitor strength, conversion, install velocity, and ranking signals measured elsewhere in the product (the ASO Score, keyword rank charts, competitor matrix).
Common workflows
"What's the biggest gap I'm missing?"
Open the Untapped reach panel, sort by MaxReach, tick the top 3-5 keywords. Click Generate. Compare the AMEND variant's TMS gain against the REWRITE variant's. Save whichever reads naturally.
"Will this rewrite cost me reach?"
Paste your candidate copy into the editor. Watch the ledger for any lost chips. If the lost keywords carry meaningful MaxReach, your rewrite shrinks the eligible pool — even if it reads better.
"A/B copy for the next release"
Save three drafts — current copy, AMEND variant, manual rewrite. Switch between the cards to compare TMS deltas side-by-side. Take the winner into App Store Connect or Play Console yourself; nothing is published from the simulator.
Reasonable questions
Why does the same draft sometimes show different TMS values?
Volume figures refresh weekly (Sunday 05:00 UTC). If a snapshot job ran between two saves, the same draft can produce a slightly different TMS — which is actually useful signal. It tells you the underlying market shifted, not your copy.
Why is my keyword still listed as uncovered when I added it to the description?
The simulator's coverage is a contiguous-token regex match (e.g. {photo editor}). On iOS, Apple does compose tokens across the title and keyword field, but our simulator doesn't credit cross-field composition yet. Workaround: add multi-word phrases as a single comma-segment in the keyword field on iOS, or as a contiguous phrase in your description on Android.
Does the simulator publish anything to the stores?
No. Nothing leaves the simulator. To ship a draft, copy the field text into App Store Connect or Google Play Console yourself.
Can I share a saved draft with a teammate?
Not yet — saved drafts are per-user. If you need shared review, copy the description text into your team's tool. Tracking the request.
What happens to the +X searches/month estimate if I'm in a small market?
For markets without a real volume provider (today: every iOS market and a handful of Android ones), the simulator falls back to a heuristic estimate that blends autocomplete depth, result density, and competitor strength. Numbers in those markets are best read as relative — comparing keywords to each other — not absolute search counts.
Open the simulator.
Numbers are clearer when you read them on your own listing.
Open ASOScan Pick an app, then "Keywords · Simulator"